Not the most engaging moment or pose. The feeling of profound contemplation just isn't that strong. He could be watching a pretty girl or fighting a headache. Also, the tent rope is incident with a shadow on his face -- looks like it's going through his head. Sorry to nitpick, but I think had you been a bit more careful or persistent, you could have gotten a better shot.
Nicely candid. This is one of those images that could do with a lot of grain, especially as you have chosen a more off grey to sepia tone than pure B&W. The tent tie (cable) is running straight through his head via the mouth.